Recently GF Beranek and myself looked through some of the second growth redwood groves along the Navarro River in Mendocino County. There are many redwoods over 240 feet, with the tallest found topping out at 275 feet. It grows about ten miles from the Pacific between State Route 128 and the Navarro River. This tree is about 150 years old with a diameter of ... five feet. Amazing.

Certainly this tree should reach 300 feet in height before it is 200 years old.

I assume this is an exceptional height for second growth but do not see much documentation on this subject.

Mark-Somewhere around the house I have an image of a stand of redwoods growing at the New Zealand Institute of Forestry near Rotorua, that were planted in the very early 1900's, and had by the time I took the picture in 1979, grown to over 200' in height (sign said 206). That's not saying they do, or don't grow that fast in northern California, but certainly provides a sense of their capability...

The redwoods (Sequioa) at Whakarewarewa, Rotorua are pushing 72 m (236 ft) at around 110 years since planting [1]. Chris Earle considers these to be the tallest known horticultural (i.e. deliberately planted) conifers in the world [2]. The second tallest (known) planted conifer is a Douglas fir in a small plantation at Mt Peel Forest Estate, South Canterbury - BVP measured this at 69.6 m (227 ft) in 2013 about 140 years since planting [3]. I have LIDAR data for both sites that confirm those heights.

The tallest planted trees in the world are, however, Eucalyptus, not redwoods. There is a blue gum (E. saligna) in Magoebaskloof, South Africa, planted around 1910 that reached 81.5 m (267 ft) in 2013 [4]. A mountain ash near Dunedin, NZ (E. regnans) either planted in 1869, or possibly secondary growth from those plantings was measured by Sillet and BVP at 81.26 m (266.6 ft) in 2014 [5].

However, the record for growth probably stands with mountain ash in its native lands: Brett Mifsud measured a 87 m tree in Victoria, Australia that naturally regenerated after fires in 1926 - 285 ft in 81 years [6].

MarkGraham wrote:Recently GF Beranek and myself looked through some of the second growth redwood groves along the Navarro River in Mendocino County. There are many redwoods over 240 feet, with the tallest found topping out at 275 feet. It grows about ten miles from the Pacific between State Route 128 and the Navarro River. This tree is about 150 years old with a diameter of ... five feet. Amazing.

Certainly this tree should reach 300 feet in height before it is 200 years old.

I assume this is an exceptional height for second growth but do not see much documentation on this subject.

Mark, I have never seen 2nd growth this tall for redwood. Those trees are exceptional.

Good research. Maybe there is a second growth redwood over 300 feet somewhere in California. Have you seen any kind of age-height growth curve for an ambitious redwood tree? Looks like they can get to 300 feet in 200 years then really slow down. Seems to take at least another 400 years to get to a "Top 100" height of around 355 feet.

An update on the Whakarewarewa redwoods - Recently released Lidar data revealed the location of the tallest tree in the grove in 2010. Laser rangefinder (Nikon Forestry 550) measurements last week showed that tree to be 73.4 m (241 ft) tall at 116 years of age, and probably still growing around 1 ft per year at least.

I also came across published Lidar data for a Douglas Fir permanent sample plot near Nelson, New Zealand. Those trees, planted in 1949, exceeded 60 m, with the tallest measured by Lidar at 66.8 m (albeit on sloping terrain). Almost 220 ft in 68 years.

Thanks for doing a more accurate measurement. I measured this tree from the river bank, looking toward the tree and the road, and must have picked up a relatively taller top uphill across the road when fanning the top.